dvbdate: fix compilation error with glibc 2.31

as stime func doesn't exists anymore in newer versions of glibc >= 2.31 due
to obseletion, a replacment with clock_settime is inorder to fix the issue.

Signed-off-by: Dagg Stompler <daggs@gmx.com>

--- a/util/dvbdate/dvbdate.c
+++ b/util/dvbdate/dvbdate.c
@@ -309,7 +309,10 @@
  */
 int set_time(time_t * new_time)
 {
-	if (stime(new_time)) {
+	struct timespec s = {0};
+	s.tv_sec = new_time;
+
+	if (clock_settime(CLOCK_REALTIME, &s)) {
 		perror("Unable to set time");
 		return -1;
 	}